Light emitters, such as lasers can be used in compact optical projectors, which are used in a variety of applications. For example, such projectors may be used to cast light (e.g., structured light or unstructured light) onto an object for purposes of three-dimensional (3D) mapping (also known as depth mapping). Accordingly, light emitters (e.g., lasers) may be included in illumination assemblies to project a pattern of light (e.g., structured or unstructured) onto the object. The terms “optical” and “light” as used herein refer generally to any and all of visible, infrared, and ultraviolet radiation. An image capture assembly captures an image of the light that is projected onto the object, and a processor processes the image so as to reconstruct a 3D map of the object.
Optical projectors may, in some applications, project light through one or more diffractive optical elements (DOEs). For example, a laser device can be used for projecting a pattern that includes two DOEs that are together configured to diffract an input beam so as to at least partially cover a surface. The combination of DOEs reduces the energy in the zero-order (undiffracted) beam. In one embodiment, the first DOE generates a pattern of multiple beams, and the second DOE serves as a pattern generator to form a diffraction pattern on each of the beams.
Additionally, optoelectronic components and optical elements can be included in a single integrated package. An integrated photonics module (IPM) comprises radiation sources in the form of a two-dimensional matrix of optoelectronic elements, which are arranged on a substrate and emit radiation in a direction perpendicular to the substrate. Such an IPM typically comprises multiple, parallel rows of emitters, such as light-emitting diodes (LEDs) or vertical-cavity surface-emitting lasers (VCSELs), forming a grid in the X-Y plane. The radiation from the emitters is directed into an optical module, comprising a suitable patterned element and a projection lens, which projects the resulting pattern onto a scene.
Accordingly, light emitter packages can continue to be developed for applications in 3D scanning, gesture detection, motion sensing, facial recognition, depth sensing, time-of-flight applications, light detection and ranging (LIDAR), biomedical sensing (e.g., eye sensing, fingerprint sensing, or other anatomical feature sensing), or other uses. A CMOS imager, CCD imager, or APD detector or other detectors can detect reflections of the laser light for the functions described herein.
Additionally, light emitters (e.g., lasers) are commonly used in many modern communication components for data transmission. One use that has become more common is the use of lasers in data networks. Light emitters are used in many fiber optic communication systems to transmit digital data on a network. In one exemplary configuration, a light emitter may be modulated by digital data to produce an optical signal, including periods of light and dark output that represents a binary data stream. In actual practice, the light emitter output a high optical output representing binary highs and a lower power optical output representing binary lows. To obtain quick reaction time, the light emitter is constantly on, but varies from a high optical output to a lower optical output.
The subject matter claimed herein is not limited to embodiments that solve any disadvantages or that operate only in environments such as those described above. Rather, this background is only provided to illustrate one example technology where some embodiments described herein may be practiced.